AT&T

Sector: Communication Services

Industry: Telecom Services

AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Dallas, Texas. It operates through the following segments: Communications, WarnerMedia, Latin America, and Xandr. It is the world's largest telecommunications company by revenue and the third-largest provider of mobile telephone services in the US. The company has been consistently ranked in the top 20 on the Fortune 500 rankings of the largest US corporations by revenue. During most of the last century, AT&T Inc. was the dominant phone service in the US, although it has since lost that position of prominence. The company was incorporated as the American District Telegraph Company in St. Louis in 1878. Through a series of mergers, it became Southwestern Bell Telephone Company and finally AT&T Inc.